306.7% is the change from 209 to 850
Calculation steps:
[( 850 - 209 ) ÷ 209] x 100 = 306.7%
Formula
Percentage change = [(850 - 209) / 209] x 100
Subtract the new number by the original number
850 - 209 = 641
641 ÷ 209 = 3.0669856459330145
3.0669856459330145 x 100 = 306.7%